关于lat(I/O completion latency)、clat(complete latency)、slat(summit latency):app
lat is the total latency. slat is the time it takes to submit the IO to the kernel, clat is the time from when slat is over and until the device has completed it (and the application is notified). Hence lat is slat + clat.
一、rw_sequencerdom
identical或者sequentialide
如rw=randread:8 这样每8次io就更改一次offset。那么这个rw_sequencer控制在这8次的io时的offset。debug
二、#!/usr/local/bin/fio --debug=ioit
使用debug选项能够看到它的io的详细状况io
三、rw=randread:51200file
表示每51200次io从新取offsetservice
四、file_service_type=random:51200bug
表示每51200次io从新随机取下一个文件im